Project Summary/Abstract: Acquired hearing loss is becoming increasingly common, especially with the growth of the aging population. For many individuals, hearing loss is severe enough to warrant cochlear implantation. While many adults with cochlear implants (CIs) understand speech well through their devices, enormous unexplained variability exists in speech recognition outcomes. Unfortunately, because of this unexplained variability, clinicians are unable to predict how an individual will perform with a CI, to explain why someone has poor speech recognition with a CI, or to design appropriate rehabilitation strategies to help an individual with poor performance. Currently, only half of this outcome variability can be explained, and those factors that have been found to explain variability are limited primarily to ?bottom-up? auditory sensitivity processes related to the CI itself, or the condition of the peripheral auditory system. However, it is likely that ?top-down? cognitive and linguistic factors assist CI users to recognize speech. These factors should explain additional variability in CI outcomes, but they have not previously been a research focus in adult CI users. This project capitalizes on the expertise of investigators, mentors, and consultants with broad experience studying bottom-up and top-down processes. The overall project objective is to determine how top-down skills relate to speech recognition for adult CI users, how these skills interact with bottom-up processes, and how the experience of auditory deprivation affects top-down abilities. Aim 1 will examine the contributions of bottom-up auditory sensitivity and top-down linguistic knowledge on recognition of speech materials. Aim 2 will investigate the effects of top-down cognitive skills on sentence recognition. Aim 3 will compare top-down cognitive and linguistic skills between adult CI users and age- matched normal-hearing peers, which will reveal the effects of auditory deprivation on these top-down abilities. The findings from this research project will have important theoretical implications because they will shed light on the processes used by adults with hearing loss to recognize speech, as well as the effects of auditory deprivation on relevant top-down skills. The findings and training provided by the proposed career development award will enhance the PIs prospects as a future independent investigator seeking to improve outcomes for CI users. Results will lay the groundwork for future studies incorporating individualized rehabilitation protocols for adults with CIs to optimize their speech recognition performance.